Bigger Isn't Always Better for Wildlife Reserves

Lynne Peeples | November 10, 2010 02:59am ET

While setting aside massive swaths of land would seem to provide
powerful strongholds for biodiversity, a new study finds that such
reserves often don't reach their full conservation potential because of
poor placement — they are put in areas that are convenient for people
to avoid, but not for threatened species to thrive.

Still, the study researchers say that there are other key roles that the world's largest reserves play in environmental conservation, and highlight the importance of defending them from growing threats.

"These protected areas might not be representing a lot of rare
species, but they contribute in other ways," said Lisette Cantu-Salazar
of the University of Sheffield in England, and lead author of the study
recently published in the journal BioScience.

Some payoffs

Cantu-Salazar, along with her Sheffield colleague Kevin J. Gaston,
took a detailed look at 63 large conservation areas around the world
that each covered at least 9,700 square miles (25,000 square
kilometers) — an area approximately the size of Vermont. As a whole,
these legally protected areas account for less than 0.05 percent of the
planet's 120,000-plus reserves, but the large reserves account for more
than a quarter of the total protected area, about 22 million total
square kilometers (8.5 million square miles).

The researchers found that substantial size paid off in several ways for reserves, from large-scale wilderness preservation to safeguarding ecosystem services to protecting intact regional populations of species.

They note that the areas may be particularly important for certain
species in the face of shifting temperature and precipitation patterns
with global warming, providing them protected space to migrate with the changing climatic conditions.

Fewer miles of border relative to bounded area also makes it more
difficult for destructive human activities to penetrate into a large
protected area, whereas it can be easy to extract resources such as oil
and lumber from smaller ones, Cantu-Salazar said.

However, she pointed to at least one exception — in Numan, Nigeria —
in which hydrocarbon prospecting has infiltrated a very large protected
area. "We must not be overconfident in thinking that these areas are
remote and will never be touched," she said. "This could happen to
other protected areas too."

Will Turner, director of Global Priorities at Conservation International,
a nonprofit environmental organization in Washington, D.C., also noted
the importance of large protected areas for carbon storage for keeping
both intact forests and below ground stores undisturbed.

"These habitats are providing important services for people," said
Turner, who was not involved in the new study. "But they aren't all
ideally situated for the best return on investment in terms of conserving biodiversity."

While certain temperate areas are well-covered and important for
safeguarding large numbers of species, such as bird breeding ranges
along the northern coasts of North America, others are tragically
underrepresented, Turner said. There are no huge protected areas
covering Southeast Asia or large swaths of Africa, he noted, despite
these regions' "phenomenal importance" for biodiversity with great
numbers of threatened species. The Congo forests of Africa, for
example, aren't represented at all.

Best places to protect?

Turner added that only one large protected area covers one of the
500 key sites designated by the Alliance for Zero Extinction, a joint
initiative of 52 biodiversity conservation organizations around the
world that aims to identify the last remaining places for critically endangered species.

"The problem is that few large protected areas are in high
population, productive areas," said Cantu-Salazar. "Rather, they tend
to be established in regions that don't interfere with human
activities." Humans tend to like coastal areas, for example, as do many
threatened species, but large coastal areas rarely end up on the rolls
of protected spaces.

Cantu-Salazar noted the need for adding new protected areas to the
list, but also the difficulty in identifying such areas. "There simply
aren't many wild areas left," she said.

Furthermore, the protected areas that have already been established are under a lot of pressure.

"There's not enough money to maintain many of them, but they are all
very important," said Cantu-Salazar. "We need to make more assessments
of how well they are covering not only species richness but also these
other kind of biodiversity features so that their value can be taken
into account." Species richness refers to the number of different
species represented.

"It's clear that very large protected areas don't solve the entire
conservation problem. They are not a silver bullet," added Turner,
highlighting the potential to integrate different kinds of conservation
strategies, including coordinated networks of smaller areas where
larger ones can't be established.

While the study only addressed terrestrial protected areas, Turner
suggested that the lessons could be applied to freshwater and marine
areas as well: "There is lots of biodiversity in the oceans that could really benefit from a marine equivalent."